Refrigeration system including refrigerant metering means

ABSTRACT

A refrigeration system including a refrigerant expansion or metering device. The system includes a compressor, a first heat exchanger and a second heat exchanger, the metering device being disposed between the first and second heat exchangers. The device includes a vortex chamber through which refrigerant is passed. Disposed within the vortex chamber is a heat sensitive plunger operable to vary the path of flow and to vary the rate of flow through the vortex chamber. Refrigerant is passed in heat transfer relation with the plunger which has a source of heat associated therewith. As the quality of the refrigerant varies, so does the heat transfer rate between the refrigerant and plunger.

Morgan May 15, 1973 REFRIGERATION SYSTEM INCLUDING, REFRIGERANT METERING MEANS Inventor: Robert D. Morgan, Syracuse, N.Y.

Assignee: Carrier Corporation, Syracuse, N.Y.

Filed: Mar. 3, 1971 Appl. No.2 120,573

US. Cl ..62/202, 62/225 Int. Cl ..F25b 41/04 Field of Search ..62/1 15, 202, 204,

References Cited UNITED STATES PATENTS 3/1968 Rhea ..62/l60 Primary ExaminerMeyer Perlin Attorney-Harry G. Martin & J. Raymond Curtin [57] ABSTRACT A refrigeration system including a refrigerant expansion or metering device. The system includes a compressor, a first heat exchanger and a second heat exchanger, the metering device being disposed between the first and second heat exchangers. The device includes a vortex chamber through which refrigerant is passed. Disposed within the vortex chamber is a heat sensitive plunger operable to vary the path of flow and to vary the rate of flow through the vortex chamber. Refrigerant is passed in heat transfer relation with the plunger which has a source of heat associated therewith. As the quality of the refrigerant varies, so does the heat transfer rate between the refrigerant and plunger.

3 Claims, 1 Drawing Figure PATENTEDMAYISHYS BJ'QZJ'OA INVENTOR. ROBERT D. MORGAN ATTORNEY REFRIGERATION SYSTEM INCLUDING REFRIGERANT METERING MEANS BACKGROUND OF THE INVENTION Refrigeration systems employ, as a means for expanding the relatively high pressure liquid refrigerant leaving the system condenser, either a fixed restrictor, commonly known as a capillary tube, or a variable restrictor, such as a thermal expansion valve. While fixed restrictors are relatively inexpensive, their lack of adaptability to change in system load limits their usefulness. On the other hand, the variable restrictor, such as a thermal expansion valve, incorporates a controlling mechanism for varying the valve setting in response to changes in refrigerant quality exiting from the evaporator due to variations in load conditions in the system. However, variable restrictors are relatively expensive. As used herein the term quality" includes the temperature and/or the ratio between the weight of vapor and of the refrigerant at a particular point in the cycle.

The invention herein disclosed relates to a novel expansion divice, one that is relatively inexpensive to manufacture and relatively maintenance free, and one that is responsive to changes of quality of the refrigerant exiting from the evaporator.

SUMMARY OF THE INVENTION This invention relates to refrigeration systems and more particularly, to an improved expansion means for refrigeration systems.

The present invention may be employed in a refrigeration system including a compressor, a first heat exchanger for receiving refrigerant discharged by the compressor, and a second heat exchanger connected to the suction side of the compressor. A fluid regulator communicates the first heat exchanger with the second heat exchanger. Relatively high pressure liquid refrigerant flows from the first heat exchanger through the fluid regulator, the refrigerant leaving the regulator as a relatively low pressure mixture of liquid and gas.

The fluid regulator forms a vortex chamber through which the refrigerant passes enroute to the second heat exchanger. The refrigerant inlet to the chamber is in substantially tangential communication therewith. The refrigerant passing through the chamber undergoes an approximate 90 change in direction.

Disposed in the chamber, transverse to the path of flow of the refrigerant, is a movable member such as a heat sensitive plunger. Control means, operable to selectively withdraw the plunger from the chamber or project the plunger farther into the chamber, function in accordance with changes in the quality of the refrigerant leaving the second heat exchanger. When the plunger is substantially withdrawn from the chamber, the vortex effect on the refrigerant flow is at its maximum, the refrigerant flow through the chamber being greatly impeded. As the plunger is projected into the chamber, the vortex effect is reduced, the refrigerant flow through the chamber being thereby increased.

Heating means are placed about the plunger. The control means includes housing means to pass the refrigerant in heat transfer relation with the heat sensitive plunger means. As the ability of the refrigerant to absorb heat from the heat sensitive plunger is reduced, the plunger expands so as to project into the vortex chamber. Conversely, as the ability of the refrigerant to absorb heat from the plunger as it passes in heat transfer relation therewith increases, the plunger will be withdrawn from the vortex chamber.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE of the drawing is a schematic view, partially in section, of a refrigeration system incorporating the novel fluid regulator.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the single FIGURE of the drawing, there is shown a refrigeration system 10 employing the novel refrigeration expansion device 15 herein disclosed. The refrigeration system 10 is typical of the type used with air conditioning units, such as a room air conditioner. Refrigeration system 10 has a suitable refrigerant compressor 11 which, while illustrated as a reciprocating compressor, may comprise any suitable compressor such as a rotary, centifugal, etc. Refrigerant line 12 conducts the relatively high pressure gaseous refrigerant discharged from compressor 11 to a first heat exchanger 13, functioning as the system condenser.

The high pressure, gaseous refrigerant condenses in the first heat exchanger 13 by passing therethrough in heat transfer relationship with a relatively cold medium such as air. The liquid refrigerant formed thereby passes to the system expansion or metering means 15 via conduit [4.

Expansion device 15 reduces the pressure of the liquid refrigerant and controls the flow thereof to the remaining portion of the system. A detailed discussion of the novel expansion device 15 will be found hereinafter.

The reduced pressure liquid refrigerant is fed via line 16 to a second heat exchanger 17 functioning as the system evaporator. The thermal interchange effected by evaporator 17 between the refrigerant and the medium being cooled, for example air, vaporizes or evaporates refrigerant while extracting heat from the medium being cooled. A suitable circulating means such as a fan (not shown) may be provided for bringing the medium being cooled into heat transfer relation with the refrigerant in the evaporator 17. Vaporized refrigerant leaving evaporator 17 returns through lines l8'and 18' to the inlet or suction side of the compressor 11.

The refrigerant expansion or metering means 15 disclosed herein is a vortex type fluid regulator. The regulator cmprises a shell 19 forming a generally cylindrical vortex chamber 20. Refrigerant line 14, which connects to inlet 21 in the peripheral wall of shell 19, discharges during system operation a stream of liquid refrigerant into vortex chamber'20. Inlet 21 is in substantially tangential communication with chamber 20. Outlet 22 in end wall 23 of the regulator communicates with refrigerant line 16. As is manifest, refrigerant entering vortex chamber 20 undergoes an approximate change in direction for discharge through outlet 22 into line 16.

Heat sensitive means 24, such as a rod or plunger, is movably disposed in chamber 20 transverse to the flow path of the refrigerant. The purpose of heat sensitive means 24 is to vary the vortex effect created in chamber 20 and hence vary the discharge of refrigerant to line 16, thence to evaporator 17. Control means associated with the heat sensitive plunger acts to selectively withdraw or project the plunger from or into chamber 20 in response to changes in temperature of the refrigerant exiting from the evaporator 17. As plunger means 24 is projected into chamber 20, the vortex effect on the refrigerant flow is reduced; plunger means 24 reduces the restricted effect of a vortex flow path. Conversely, as plunger means 24 is withdrawn from chamber 20, the vortex effect on the refrigerant flow is increased. Thus at peak cooling loads, it is desirable for heat sensitive means 24 to extend fully into chamber 20, while at minimal cooling loads on the system, it is desirable for plunger means 24 to be substantially completely withdrawn from the chamber 20 and thus the refrigerant flow therethrough is greatly impeded as de-' sired. Heat sensitive plunger means 24 is preferably formed from a substance having a high coefficient of expansion, such as aluminum or brass.

Shell 19 of expansion means 15 includes a portion 25 which defines a path of flow 25 for refrigerantof the system. In a preferred embodiment, the refrigerant passing through shell 19 is transmitted from evaporator 17 to compressor 11. Associated with plunger 24 is a source of heat, such as electric heating ring 26. Preferably heating ring 26 will be energized upon energization of the compressor of system 10. O-ring 27 prevents flow of refrigerant from flow path 25' into vortex chamber 20. Cap member 28 is provided to prevent plunger 24 from expanding or contracting, except into or from chamber 20.

The gas passing through path 25 flows in heat transfer relation with heat sensitive plunger 24. If the load on the system increases, the gas passing through evaporator 17 will be completely vaporized and the superheat of the gaseous refrigerant will be increased. The ability of the superheated gas to absorb heat from the heat sensitive plunger 24, as it passes in heat transfer relation therewith, is decreased. The plunger will thus expand to a greater degree as it is heated by heating ring 26 and be thereby projected into the vortex chamber to increase the flow of refrigerant therethrough by decreasing the vortex effect.

Conversely, as the load on system decreases, the refrigerant gas passing through evaporator 17 will not be superheated to the same degree and if the load decreases substantially, the entire charge of refrigerant passing through the evaporator may not be vaporized. The ability of the refrigerant to absorb heat as it passes in heat transfer relation with the heat sensitive plunger is thus increased. As heat is removed from plunger 24, it will contract and withdraw from vortex chamber 20 so as to decrease the flow of refrigerant passing therethrough.

The novel expansion device is relatively inexpensive to manufacture and is relatively maintenance free. Essentially all moving parts have been eliminated from the expansion device so as to increase the reliability of performance of the device.

While I have described and illustrated a preferred embodiment of my invention, it will be understood that my invention is not limited thereto, but may be otherwise embodied within the scope of the following claims.

I claim:

1. A refrigeration system comprising a compressor, a first heat exchanger, refrigerant metering means, and a second heat exchanger connected in series to form a refrigerant flow cycle, said refrigerant metering means 4 including:

a. a fluid regulator forming a vortex chamber through which refrigerant passes enroute to said second heat exchanger, said vortex chamber having plunger means movably disposed therein, said plunger means being heat sensitive; and

b. control means to vary the position of said plunger in said vortex chamber, in response to the quality of refrigerant at a predetermined point in said cycle to vary the path of flow and to vary the rate of flow of said refrigerant through said vortex chamber in accordance with changes in system cooling load, including means to pass refrigerant flowing from said second heat exchanger to said compression means in heat transfer relation with said heat sensitive plunger means; and heating means associated with said plunger means, the flow of refrigerant passing in heat transfer relation with said plunger means operating to remove heat supplied to said plunger means by said heating means, the amount of heat removed from said plunger means varying in accordance with changes in the system cooling load.

2. A refrigerant metering device employed in refrigeration systems, operable to expand relatively high pressure liquid refrigerant comprising:

a. a fluid regulator forming a vortex chamber through which refrigerant is passed;

b. refrigerant inlet means into said vortex chamber;

c. refrigerant outlet means from said vortex chamber;

d. heat sensitive plunger means movably disposed in said vortex chamber to vary the flow path of refrigerant therethrough;

e. heating means associated with said plunger means;

and

. means to define a flow path for said refrigerant to pass in heat transfer relation with said plunger means, the flow of refrigerant passing in heat transfer relation with said plunger means operating to remove heat supplied to said plunger means by said heating means, the amount of heat removed from said plunger means varying in accordance with changes in the system cooling load.

3. A method of regulating the flow of refrigerant in a refrigeration system comprising a compressor, a first heat exchanger and a second heat exchanger comprising the steps of:

a. energizing said compressor to circulate said refrigerant through said system;

b. directing the flow of refrigerant from the first heat exchanger to the second heat exchanger through a path including a vortex;

c. supplying heat to a heat sensitive plunger movably disposed within the vortex; and

d. passing the refrigerant of said system in heat transfer relation with said heat sensitive plunger, the flow of refrigerant passing in heat transfer relation with said plunger means operating to remove heat supplied to said plunger means by said heating means, the amount of heat removed from said plunger means varying in accordance with changes in the system cooling load.

I i 4 l 

1. A refrigeration system comprising a compressor, a first heat exchanger, refrigerant metering means, and a second heat exchanger connected in series to form a refrigerant flow cycle, said refrigerant metering means including: a. a fluid regulator forming a vortex chamber through which refrigerant passes enroute to said second heat exchanger, said vortex chamber having plunger means movably disposed therein, said plunger means being heat sensitive; and b. control means to vary the position of said plunger in said vortex chamber, in response to the quality of refrigerant at a predetermined point in said cycle to vary the path of flow and to vary the rate of flow of said refrigerant through said vortex chamber in accordance with changes in system cooling load, including means to pass refrigerant flowing from said second heat exchanger to said compression means in heat transfer relation with said heat sensitive plunger means; and heating means associated with said plunger means, the flow of refrigerant passing in heat transfer relation with said plunger means operating to remove heat supplied to said pLunger means by said heating means, the amount of heat removed from said plunger means varying in accordance with changes in the system cooling load.
 2. A refrigerant metering device employed in refrigeration systems, operable to expand relatively high pressure liquid refrigerant comprising: a. a fluid regulator forming a vortex chamber through which refrigerant is passed; b. refrigerant inlet means into said vortex chamber; c. refrigerant outlet means from said vortex chamber; d. heat sensitive plunger means movably disposed in said vortex chamber to vary the flow path of refrigerant therethrough; e. heating means associated with said plunger means; and f. means to define a flow path for said refrigerant to pass in heat transfer relation with said plunger means, the flow of refrigerant passing in heat transfer relation with said plunger means operating to remove heat supplied to said plunger means by said heating means, the amount of heat removed from said plunger means varying in accordance with changes in the system cooling load.
 3. A method of regulating the flow of refrigerant in a refrigeration system comprising a compressor, a first heat exchanger and a second heat exchanger comprising the steps of: a. energizing said compressor to circulate said refrigerant through said system; b. directing the flow of refrigerant from the first heat exchanger to the second heat exchanger through a path including a vortex; c. supplying heat to a heat sensitive plunger movably disposed within the vortex; and d. passing the refrigerant of said system in heat transfer relation with said heat sensitive plunger, the flow of refrigerant passing in heat transfer relation with said plunger means operating to remove heat supplied to said plunger means by said heating means, the amount of heat removed from said plunger means varying in accordance with changes in the system cooling load. 